Rebuilt the Sunburst

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grandpaul said:
How about a photo?

Maybe you have problems with the cam follower bore as well?
Click to expand...
Maybe yes, I have to tcheck everithyng tomorow, but I remember a few years ago a post about a bad batch of PW3 camshaft or followers?
I don't think there is a problem with the cam follower bore becouse there are two followers in each bore and only one is affected.
Thanks
Yves
 
I have no specific 'facts' but I also recall an issue with the hardness of Norton cams in recent years, such that Andover Norton went over to cast iron - I think?
I'm sure it's been covered here before?

My Maney cam is iron.
 
B+Bogus said:
I have no specific 'facts' but I also recall an issue with the hardness of Norton cams in recent years, such that Andover Norton went over to cast iron - I think?
I'm sure it's been covered here before?

My Maney cam is iron.
Click to expand...
PW3 cams are chilled cast iron like most cams that are available now (e.g. DNC Dave Newman Camshafts sold by Andover Norton).
The PW3 cam has a lot of lift on the exhaust side. This can cause a few problems, especially in combination with "aftemarket" heads and /or cylinders:
1) the exhaust rocker touches the "roof" of the head at full lift
2) the exhaust cam follower touches the top of the tunnel at full lift
3) the exhaust valve spring becomes "coil bound" at full lift
Any of these will cause premature cam wear.

Yves, I seem to remember that you already experienced problem number 1 with your first Fullauto head and your first PW3 cam.

Bert
 
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yves norton seeley said:
Hi there
Bad surprise to day, I strip the engine and I discover a unusual wear (3mm) on the last lobe from the camshaft, the other lobes looks OK, the camshaft is coming from Mike Hemings and is a PW3.
The follower from this lobe is also scratched.
Do some members have the same problem?
Yves
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There was a run of time where some AN followers were soft, probably around the same time that Sunburst was built. Jim Comstock did some testing

Cam and follower tests.

I have been experimenting with alternative cam followers for my engine. Here is some cuts from the spintron testing. Over the past 2 days the hardweld followers have ~ 16 hours of runtime.
www.accessnorton.com www.accessnorton.com
 

Cam followers - Andover to the rescue?

This just popped into my inbox, kudos to Andover for the investment in time and research: "With metallurgists on both sides of the Atlantic looking at this, a new material was formulated that would allow casting but was a little under the required hardness we needed. This was spotted by the...
www.accessnorton.com www.accessnorton.com
 
yves norton seeley said:
Hi there
Bad surprise to day, I strip the engine and I discover a unusual wear (3mm) on the last lobe from the camshaft, the other lobes looks OK, the camshaft is coming from Mike Hemings and is a PW3.
The follower from this lobe is also scratched.
Do some members have the same problem?
Yves
Click to expand...
Yes, end of season 2015 my PW3 the drive side lobe was completely shot. Camshaft was actually supplied by Norman White, but was from joint supply with Mick.

I went with a Webcam from Jim Comstock. It makes good power, but I like the PW3 characteristics and I still want a good PW3 cam replacement.
 
SteveA said:
Yes, end of season 2015 my PW3 the drive side lobe was completely shot. Camshaft was actually supplied by Norman White, but was from joint supply with Mick.

I went with a Webcam from Jim Comstock. It makes good power, but I like the PW3 characteristics and I still want a good PW3 cam replacement.
Click to expand...
Why not use your old PW3 as a core and lobes copied in hard weld?
 
johntickle said:
PW3 cams are chilled cast iron like most cams that are available now (e.g. DNC Dave Newman Camshafts sold by Andover Norton).
The PW3 cam has a lot of lift on the exhaust side. This can cause a few problems, especially in combination with "aftemarket" heads and /or cylinders:
1) the exhaust rocker touches the "roof" of the head at full lift
2) the exhaust cam follower touches the top of the tunnel at full lift
3) the exhaust valve spring becomes "coil bound" at full lift
Any of these will cause premature cam wear.

Yves, I seem to remember that you already experienced problem number 1 with your first Fullauto head and your first PW3 cam.

Bert
Click to expand...
Hallo Bert,
This Fullauto head was assembled by jim Comstock, must be good no?
yves
 
SteveA said:
Yes, end of season 2015 my PW3 the drive side lobe was completely shot. Camshaft was actually supplied by Norman White, but was from joint supply with Mick.

I went with a Webcam from Jim Comstock. It makes good power, but I like the PW3 characteristics and I still want a good PW3 cam replacement.
Click to expand...
hello Steve,
Do you find a reason why this happens?
Yves
 
I can not accept that almost 130 years after the making of the first camshaft and followers, some producers put some bad stuff on the market.
Where is the quality control. Thanks Jim Comstock for all testing you do but this is not your job, this is the job from the producers!
This is my second PW3 camshaft with issues, the first one broke in two pieces.
How many engines blow up becouse of this?
Not happy.
Yves
 
Understandably so , there can be at least two ways this can happen, someone previously dropped the cam onto a hard floor and/or combined with the cam being over hardered making it brittle. Sorry for your bad luck.
 
Fast Eddie said:
Why not use your old PW3 as a core and lobes copied in hard weld?
Click to expand...
Well....can of worms there FE....

The cam had been mapped by Snotzo before installation, lets just say it didn't seem accurate to the PW intended spec.
 
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yves norton seeley said:
hello Steve,
Do you find a reason why this happens?
Yves
Click to expand...
To my satisfaction no, but various things may have contributed.

We are aware of issues with the steep ramps of the PW3 if the motor is revved too high.

My installation used standard AN flat followers and was revved mostly to 7500rpm but sometimes up toward 8000rpm (one observed occasion of a missed gear 8500) and straight 40 mineral oil 1970s style.

The Webcam was installed with asymmetrically radiused followers and I have used synthetic oils since then (currently Bel Ray V Twin oil).

But let's not make this a camshaft thread :oops:
 
SteveA said:
To my satisfaction no, but various things may have contributed.

We are aware of issues with the steep ramps of the PW3 if the motor is revved too high.

My installation used standard AN flat followers and was revved mostly to 7500rpm but sometimes up toward 8000rpm (one observed occasion of a missed gear 8500) and straight 40 mineral oil 1970s style.

The Webcam was installed with asymmetrically radiused followers and I have used synthetic oils since then (currently Bel Ray V Twin oil).

But let's not make this a camshaft thread :oops:
Click to expand...
I use also Bel Ray V twin oil
To day I open the cases, main bearings are OK, crankshaft and rod's are OK, the only damage I can see are some scratches on the pistons and on the bore.
Tomorrow I will make some pics
Yves
 
unnamed (3).jpg

Here is the disaster

unnamed.jpg

folower from this lobe

soupapes.jpg

Modified Black Diamond valves tips ready for JS beehive springs

Hi there
here be the pics from the PW3 camshaft and folower
Your opinion please?

Mohamed and Mustafa and there camel arrive in a village after a long journey in the desert.
They are very thirsty and hungry so the go to the restaurant and order drinks and food and say to the waiter:
- Give us camel water and food also please.
After a good diner they ask the waiter if there is a whorehouse in the village?
- No sirs, but there is Aisha, she was a hooker at the second world war, she is very old and totaly blind, you can find here at the last house from the village.
Mohamed and Mustafa and the camel walk to the house of Aicha and she agree to do the job.
Mohamed go as first and Mustafa second.
After satisfaction Mohamed and Mustafa put the camel in the house.
Aisha make a lot of noise: more! more!
After a while Aisha come out are room and say:
-Mohamed you pay 50 dollars, Mustafa also 50 dollars and your friend the hunchback with his suede jacket, he receive for free.

Yves
 
Opinions on the cam and lifter Yves? Well I’m no expert, but I think they’re worn...;)

Ok, seriously, my guess would be that as the other cam lobes appear to look ok, the cam material is not suspect. Therefore, my money is on a soft lifter being the root cause.
 
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This was the factory cam from my 74 850 at about 30,000 miles. Odd that it's the same lobe as yours. I don't remember the lifter being as bad as yours though, but I replaced all of them when I replaced the cam.

Rebuilt the Sunburst
 
That is a horrible cam lobe & lifter, but is it a manufacturing defect? Bad materials? Too much spring tension (I think not)...
 
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